The typical injection pump system has a tank or reservoir of the chemical to be injected into a system, a pump for injecting metered doses or a continuous flow of the chemical into the system, and a power source for the pump. For example, it is well known in the art to provide corrosion protection for pipelines by injecting an effective amount of a corrosion inhibitor into the fluid stream. Pipeline corrosion can cause enormous environmental and financial cost.
It is well known in the art to power these injection pumps with regular alternating current brought to the pump by conventional power lines. However, chemical injection pumps are often located in the field where electrical power is not readily available or oil or gas throughputs are such that bringing power to the field location is not economical.
In the past, some injection pumps have been operated by the gas pressure of a natural gas pipeline. However, these injection devices are not easily controlled. They are usually operated continuously, which results in the injection of excessive amounts of corrosion inhibitor. Needlessly operating the gas pump wastes the natural gas, which is vented to the atmosphere after using the work done by the pressure drop. A typical gas operated pump currently costs about 1,500 U.S. dollars (consumer value) in natural gas annually per injection pump. Furthermore, these gas operated pumps may soon be required to meet tough new government mandated regulations relating to environmental pollution that limit the emissions of volatile organic components (VOC) such as butane, propane, and methane (natural gas).
The need for corrosion protection is also important for downhole treatment of oil and gas wells. As an oil field or gas field is depleted, increasing amounts of water enters the field formations. The increasing proportions of water in the produced product causes more internal corrosion of downhole tubulars, pipelines, and storage tanks.
In some cases the injection pump is operated by the beam pump of the oil well. A beam operated injection pump is a lever-racket type system with a metal rod from the pump to the walking beam of the oil well pump jack. As the walking beam is moved up and down, the metal rod moves the lever on the injection pump. However, these systems can require substantial mechanical maintenance, there is no good way to control of the dosage of chemical injected, and they are prone to leak the chemical.
In a batch process for treating the downhole tubing called "truck treating," a truck is driven to each well location, an amount of chemical is pumped into the well, and the chemical is flushed downhole with water carried on the truck. This batch treatment is usually performed about one a week or so. Truck treating is expensive and time consuming to perform, and thus it is often not performed with sufficient frequency to protect the downhole tubing.
Because of the problems and expenses associated with the prior art injection systems, many pipelines and wells have not been provided any corrosion inhibitors. For example, the smaller gathering lines of many oil and gas fields are not provided with any corrosion inhibitor injection devices.
Thus, there is a long-felt need for a low cost, low maintenance, and simple system for injecting dosed amounts of fluids. There has also been a long-felt need for using an alternative energy source for powering the pump system for injecting the chemicals.